用偏移尾座法车削圆锥时，如果工件的圆锥半角相同，尾座偏移量即相同。( )
参考答案：错
We _________ in this school for about two years .
A. study B. studied C. have studied
溃疡并发幽门梗阻时的护理措施是
A．记出入液体量
B．忌胃肠减压
C．减少补液
D．流质饮食
E．每餐前洗胃
